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Long-Read Sequencing

Comprehensive Analysis of Hemophilia (CAHEA)

One-Stop Genetic Solutions for Hemophilia A and B

Challenges in Standard Hemophilia Testing

The clinical workflow for hemophilia patients and carriers is complex. Standard coagulation assays (PT, APTT, and factor assays) take several steps and frequently lack the sensitivity required for accurate carrier screening.

Information derived from reference ¹

While molecular testing provides more definitive results, it relies on a fragmented, stepwise methodology. Since hemophilia is caused by a wide spectrum of variants, multiple molecular assays are typically required.

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Current approaches typically initiate testing with PCR assays for common F8 intron 1 and 22 inversions, reserving sequence analysis only for inconclusive cases. This multi-step process prolongs the time to diagnosis for probands. Meanwhile, for general screening, stopping at basic screening may miss complex variants, leaving a gap in carrier detection.

Streamline Screening and Diagnostics with LRS

Comprehensive Analysis of Hemophilia (CAHEA) is an all-in-one hemophilia A & B testing solution that detects diverse mutations. Unlike NGS and Sanger sequencing, which are often limited to small mutations, or PCR assays that target only specific variants, CAHEA offers a unified, one-stop approach with 100% accuracy in F8 ² and F9 ³ genes. This replaces complex multi-test protocols with one simple, cost-effective workflow.

Send-out Testing

When considering our send-out sequencing services:

  1. Consultation: Contact our team for the most current test specifications.

  2. Sample Preparation: Check sample types and shipment requirements to ensure high-quality results. Please check your local export regulations and logistics partners.

  3. Submission: Contact Xcelom when placing an order. Include the completed Test Request and Consent Form, along with any required documents.

Sample Requirements

Peripheral Blood: 2 mL in EDTA tube

Dried Blood Spot (DBS): 3 spots, ≥ 8mm diameter each

Long-fragment gDNA

'**For prenatal cases, please include maternal sample for STR to exclude maternal contamination.

Transport Conditions

2-8℃, arrive within 72 hours

Testing Scope

Basic Panel

Targeted detection of common structural variants in the F8 gene:

  • Intron 1/22 inversions

  • Exon 22 deletions/duplications

Comprehensive panel

Detects hemophilia related variants, including:

  • F8 gene: Intron 1/22 inversions, exon 22 deletions/duplications, P/LP/selected VUS SNVs/InDels, and selected P/LP/VUS large deletions/duplications

  • F9 gene: P/LP/selected VUS SNVs/InDels, and selected P/LP/VUS large deletions/duplications

  • VWF gene: Potentially clinically significant SNVs/InDels in exons 18-28 (the region responsible for binding factor VIII (F8))

Prenatal Comprehensive Panel

  • Detects hemophilia related variants, including:

  • F8 gene: Intron 1/22 inversions, exon 22 deletions/duplications, P/LP SNVs/InDels, and selected P/LP large deletions/duplications

  • F9 gene: P/LP SNVs/InDels, and selected P/LP large deletions/duplications

  • VWF gene: P/LP SNVs/InDels in exons 18-28 (the region responsible for binding factor VIII (F8))

Turnaround Time (TAT)

17 working days

End-to-End Technology Transfer

Berry Genomics and Xcelom provide dedicated turnkey package to bring this capability into your laboratory. We offer end-to-end support, including:

  • Lab Setup: Consultation on workflow, equipment, and customized kits.

  • Training: Comprehensive wet-lab training for your staff.

  • Bioinformatics Support: Our tailored software solutions streamline variant annotation and interpretation, automatically integrating public databases to assist with ACMG analysis.

Resources

References:

1. Johnsen JM, Fletcher SN, Dove A, et al. Results of genetic analysis of 11 341 participants enrolled in the My Life, Our Future hemophilia genotyping initiative in the United States. J Thromb Haemost. 2022;20(9):2022-2034.

2. Liu Y, Li D, Yu D, et al. Comprehensive Analysis of Hemophilia A (CAHEA): Towards Full Characterization of the F8 Gene Variants by Long-Read Sequencing. Thromb Haemost. 2023;123(12):1151-1164.

3. Shi M, Ma Y, Peng X, et al. Clinical validation and application of targeted long-range polymerase chain reaction and long-read sequencing-based analysis for hemophilia: experience from a hemophilia treatment center in China. J Thromb Haemost. 2024;22(12):3431-3447.

 

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